The introduction of combination anti-HIV therapy has produced dramatic declines in mortality and morbidity among people with HIV. Unfortunately, a significant number of patients will experience a rebound in their disease within two years of starting therapy. In many cases this virologic failure is associated with the appearance of HIV variants encoding mutations that render them resistant to the available therapies. Of additional concern is the observation that these resistant variants are found with some frequency in newly infected individuals who have never received therapy, indicating that they can spread from one person to another. This development and subsequent dissemination of resistant viruses reflects a complicated interplay among aspects of the molecular biology of HIV, the behavior of HIV-infected people and the economic and social conditions in which people with H/V/AIDS find themselves. The research goals of this proposal are to address the question "What types of behaviors are most likely to lead to the failure of combination antiretroviral therapy?" Through these studies, I will begin to integrate my laboratory, health services and social science research interests. My mentoring goals are to: 1) Provide training and support to trainees and junior faculty as they advance to research independence 2) Develop a research curriculum related to behavioral medicine. I will devote particular attention to advancing my expertise in psychometric studies. The K24 award will allow me protected time and resources to explore this series of projects and to mentor the next generation of clinical researchers.